Lecture 28: Contraction

Question 1

What is the function of cardiac muscle?

Answer 1

• Pumping of blood around the body

Question 2

What is the function of smooth muscle?

Answer 2

• to control the movement of fluids

- movement in walls of hollow organs

Question 3

What is the function of skeletal muscle?

Answer 3

• Heat
• Posture
• Movement

Question 4

What is the type of control for:

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Answer 4

Skeletal = voluntary

Cardiac & Smooth = involuntary

Question 5

Are there synapses in:

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Answer 5

Skeletal = synapses

Cardiac & Smooth = no discrete syanpses

Question 6

Are there striations in:

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Answer 6

Skeletal muscle = striations
Cardiac muscle = striations
Smooth muscle = NO striations

Question 7

Are there T-tubules in:

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Answer 7

Skeletal & cardiac muscle = T-tubules

Smooth muscle = NO tubules

Question 8

Are there gap junction in:

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Answer 8

Skeletal muscle = NO gap junctions
Cardiac muscle = GAP junctions - intercalated discs connect cells ----> heart contracts in unison ---> heartbeat
Smooth muscle
     - Single unit = GAP junctions
     - Multi uint = NO gap junctions

Question 9

What is the contraction speed for:

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Answer 9

Skeletal muscle = Fast
Cardiac muscle = Slow - continuous all at once - PACEMAKER
Smooth = Very slow - due to no t-tubules

Question 10

Is there autonomic input for:

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Answer 10

Skeletal muscle = NO

Cardiac & smooth = YES

Question 11

What is the cell structure of:

• Skeletal muscle cells
• Cardiac muscle cells
• Smooth muscle cells

Answer 11

Skeletal = multinucleate long cylindrical cells
Cardiac = mononucleate branching cells
Smooth = mononucleate spindle like cells

Question 12

Heat can be lost through:

Answer 12

= through the skin via - radiation, evaporation, conduction or convection
= blood vessels close to the skin
= sweating

Question 13

How does skeletal muscle increase body temp?

Answer 13

• Shivering

- voluntary movement in the form of exercise

Question 14

How does smooth muscle increase body temp?

Answer 14

• Vasoconstriciton = decrease in diameter of blood vessels flow —-> reduces amount of blood flow
• –> reduces heat loss through skin - diverts blood flow from perphiphery to core
• Piloerection = haris stand up on end to trap more heat

Question 15

How does smooth muscle decrease body temp?

Answer 15

Vasodilation = increase in diameter of blood vessels

——-> blood flow is diverted to skin

Question 16

How does cardiac muscle decrease body temp?

Answer 16

Contracts more forcefully to drive blood through dilated blood vessels —–> maximum heat loss

Question 17

How do sweat gland decrease body temp?

Answer 17

secretion of sweat - which then evaporates from skin and cools you down

Question 18

When your core body temp is high …….

Answer 18

blood vessels dilate

sweat glands sweat

Question 19

When core body temp is low ……..

Answer 19

blood vessels constrict

muscles shiver